The effects of neuropeptides such as vasoactive intestinal peptide (VIP), peptide histidine isoleucine (PHI), secretin, gastric inhibitory peptide (GIP), calcitonin gene-related peptide (CGRP) and calcitonin (CT) on the substance P (SP)-, acetylcholine (ACh)- or noradrenaline (NA)-mediated secretion of fluid, protein and glycoprotein (GP) from the rat submandibular glands were examined. Results : 1.VIP and its homologues on the NA-mediated secretion (1)NA-mediated secretion of fluid and protein was enhanced by VIP and secretin but not by PHI or GIP.(2)The salivaevoked in combination of VIP with NA contained mainly GP which originated from the granular tubular cells (GT). (3)The synergistic effect of the combination of VIP with NA was antagonized by pretreatment with prazosin. 2.VIP and its homologues on the SP-mediated secretion. (1)SP-mediated secretion of fluid and protein were enhanced by VIP and secretin but not by PHI or GIP.(2)The saliva evoked in combination of VIP with SP conta
… Moreined mainly GP which originated from the acinar cells (AC). 3.VIP and its homologues on the ACh-mediated secretion (1)ACh-mediated secretion of fluid and protein were enhanced by VIP and secretin but not by PHI or GIP.(2)The saliva evoked in combination of VIP or secretin with ACh contained mainly GP which originated from the AC.(3)When VIP and ACh were administered together, the enhancement of fluid secretion was inhibited by pretreatment with atropine or 4-DAMP and the enhancement of protein secretion was inhibited by pretreatment with atropine or phentolamine. (4)The enhancement of the ACh-induced secretion of fluid by secretin was inhibited by pretreatment with phentolamine or haloperidol. 4.CGRP and CT on the SP-mediated secretion (1)SP-mediated secretion of fluid were enhanced by CGRP and salmon CT but not by rat CT.(2)The synergistic effect of the combination of CGRP with SP was antagonized by pretreatment with spantide or CGRP-(8-37). These results suggest that VIP and secretin, but not PHI and GIP can enhance the secretion of fluid and protein that is mediated by SP,NA and ACh in rat submandibular gland and that CGRP and salmon CT can also enhance the secretion of fluid that mediated by SP.結果: 1. NAに対する VIPとその類似体(1)NAによる唾液と蛋白分泌の増大は、VIPおよびsecretinの前投与でみられ、PHIおよびGIPの前投与でみられなかった。(2)NAとVIPの併用投与による分泌唾液は、主に顆粒管由来のGPを含有した。(3)NAとVIPの併用による協力作用は、prazosin で拮抗した。2.SPに対するVIPとその類似体(1)SPによる唾液と蛋白分泌の増大は、VIPおよびsecretinの前投与でみられ、PHIとGIPの前投与でみられなかった。(2)SPとVIPの併用による分泌唾液は、主に腺房由来のGPを含有した。3.AChに対するVIPとその類似体(1)AChによる唾液と蛋白分泌の増大は、VIPおよびsecretin の前投与でみられ、PHIおよびGIPの前投与でみられなかった。(2AChとVIPおよびsecretinの併用による分泌唾液は、主に腺房由来のGPを含有した。(3)AChとVIPの併用による唾液分泌の増大は、atropine(ATR)および4-DAMPで、蛋白分泌の増大は、ATRおよびphentolamine(PHT)で抑制した。(4)AChとsecretinの併用による唾液分泌の増大は、PHTおよびhaloperidolで抑制した。4.SPに対するCGRPおよびCT(1)SPによる唾液分泌の増大は、CGRPおよびsalmon CTでみられ、rat CTでみられなかった。(2)SPとCGRPの併用による協力作用は、spantideおよびCGRP-(8-37)で拮抗した。これらの結果より、VIPとsecretinは、SP,NAおよびAChによる唾液と蛋白の分泌を、また、CGRPおよびsalmonCTは、SPによる唾液分泌を増大させることが示唆された。 Less